Image quality correction processing (may be called development processing) such as gamma processing, automatic white balance processing, hue correction processing dependent on an imaging mode, frequency characteristic correction processing, or noise reduction processing is performed on a pickup signal obtained from an image sensor such as a charge-coupled device (CCD), that is, image data obtained as a result of imaging (hereinafter, referred to as raw data) in order to convert the raw data into visible image signals. Further, the image signals are compressed according to an irreversible compression method and stored in a recording medium. In contrast, in efforts to avoid degradation in image quality derived from the irreversible compression and enable image quality correction desired by a user himself/herself, a proposal has been made of a method in which: the raw data is recorded in the recording medium; the raw data recorded in the recording medium is inputted to an information processing system such as a computer; and image information is produced by the information processing system (refer to Japanese Patent No. 3230291).
The amount of raw data is much larger than the amount of image data resulting from image quality correction. This poses a problem in that it takes much time to produce image information from the raw data. In order to solve the problem, a proposal has been made of a method in which when image quality correction processing is performed in the information processing system, the raw data is subjected to reduction processing in order to produce a reduced image (hereinafter, referred to as a thumbnail image), and the thumbnail image is appended to the raw data and displayed earlier than the raw data is. The method suffers from a drawback that since image quality adjustment performed in the information processing system is not reflected on a display image, if thumbnail images are used to display a list, the thumbnail images differ from original images that are objects of adjustment.
Further, the method of producing thumbnail images in an information processing system and reflecting the results of image quality correction on the thumbnail images is proposed in JP-A-2003-346143. The method described in the literature is confronted with a problem that since the information processing system has to temporarily read all raw data items, user-friendliness may be impaired during display of a list.